Sheet metal container with hemmed body end



T. M. EKSTROM Dec. 19, 1967 SHEET METAL CONTAINER WITH HEMMED BODY END Filed Nov, 15, 1965 K UN w w on w United States Patent 3,358,875 SHEET METAL CONTAINER WITH HEMMED BODY END Ted M. Ekstrorn, Rockford, Ill., assignor to J. L. Clark Manufacturing Co., Rockford, 111., a corporation of Illinois Filed Nov. 15, 1965, Ser. No. 507,929 4 Claims. (Cl. 22060) ABSTRACT OF THE DISCLOSURE For securing a molded plastic cover to a tubular sheet metal container, a short length of the metal at one end of the container is folded laterally and then reversely to form a relatively flat hem which is defined by a lip at the end of the container and by a flange terminating in a downwardly facing raw edge spaced below the lip. The cover includes a skirt telescoped over the lip and formed with a peripheral bead which is interlocked beneath the flange edge by virtue of the metal edge biting into the softer plastic of the bead. To insure effective biting engagement of the edge with the bead, the flange is depressed intermediate its ends so that the edge portion thereof is inclined away from the wall of the container and toward the bead to expose the edge more fully and to locate the edge more accurately relative to the lip and the bead.

This invention relates to a container of the type in which a skirt depending from the periphery of a cover of flexible plastic is telescoped with the end of a tubular sheet metal body and interlocked beneath a downwardly facing flange edge to fasten the cover securely to the body. More particularly, the present invention constitutes an improvement over the container disclosed in Patent No. 3,322,299, in which the flange edge interlocking with a peripheral bead on the plastic cover is the free edge of a relatively flat hem formed by folding over and reversely bending a short length of the body tube. Such bending and folding also leaves a lip on the end of the sheet metal body which is thick enough to wedge into a groove in the plastic cover and form a tight peripheral seal between the body and the cover.

The primary object of the invention is to modify the construction of the hem flange in a container body of the above character to provide for substantially greater exposure of the flange edge and to insure more effective biting engagement with the cover skirt.

The invention also resides in the novel configuration of the hem flange so as to locate the free edge more accurately relative to the body lip for assured interlocking engagement with the cover skirt in spite of wide dimensional variations inherent in manufacture by modern high speed production methods.

Other objects and advantages will become apparent as the following description proceeds, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a sheet metal container embodying the novel features of the present invention and having a portion of the plastic cover broken away.

FIGURES 2 and 3 are fragmentary cross-sections taken respectively along the lines 22 and 3-3 of FIGURE 1 showing the invention on a ten size scale.

FIGURE 4 is a view similar to FIGURE 2 showing only the plastic cover.

FIGURE 5 is an enlarged view showing the cover and the container in the course of assembly.

In the container shown in FIGURES 1 and 2 of the drawing, a generally rectangular cover 10, composed of yieldable plastic such as polyethylene, has one or more 3,358,875 Patented Dec. 19, 1967 parts which are adapted to be raised to expose an opening through which the container contents may be removed or dispensed. Depending from the top of the cover is a long peripheral skirt 11 with an outwardly projecting bead 12 formed around its exterior. The bead is of generally frusto-conical configuration and thus presents a lower inclined guide surface 13 and an upper oppositely inclined flange engaging surface 14 which, in conjunction with a vertically inclined wall 15 of the long skirt 11, forms one side of a downwardly opening, upwardly tapering groove 16 that receives the container body in final assembly. Above the upper surface 14, an inclined surface 17 and a vertical wall 18 of a second shorter skirt 19 cooperate with the underside 20 of the plastic material 21 bridging the two skirts to form the other side and the top of the groove 16.

A container body 22 is formed in a standard high speed body maker from a flat blank of thin sheet metal and, in order to achieve engagement of the body and the cover 10, a short length of material at one end of the blank is converted by well known bending techniques into a hem 23 having a cover engaging flange edge 24. Accordingly, the edge portion of the blank is bent or folded laterally to form a hem fold 25 and then is bent reversely to form a flange 26. Due to this manner of bending the blank, the hem fold 25 forms a lip of rounded cross-section which eventually defines the end of the final container body and the original raw edge of the blank is converted into the flange edge 24.

Operating in automatic sequence, the body maker forms the blank into a tubular body of any desired crosssectional shape having an interlocking and flattened seam 27 extending along one side over the full length of the body for securing together the two ends of the blank. Finally, after completion of the hemming, tubing and seaming operations, the hem is offset inwardly at '28 from the remainder of the body by cooperating inner and outer dies acting on the upper portion of the body.

In order to assemble and lock the cover 10 to the body 22, and as shown in FIG. 5, the groove 16 of the skirt 11 is placed in alinement with the hemmed end of the body and the cover is pressed downwardly until the top of the cover comes against the lip 25 of the body. During such telescoping, the lip encounters the guide surface 13 of the lower edge of the bead 12 and, due to the resiliency of the plastic, cams the skirt 11 inwardly so as to allow the hem 23 to pass. Then, as the lip begins to wedge between the walls 15 and 18 in the upper portion of the groove 16, the hem edge 24 reaches the inclined flange engaging surface 14 of the bead and the skirt expands to engage the edge for securely fastening the cover to the body. The offset 28 in the body permits the radial width of the bead 12 to be increased and the bead projects well beyond the edge 24 thereby insuring that there will be ample bead surface for engaging the edge in the final assembly.

In accordance with the present invention, the flange 26 of the hem is deformed into a novel shape, not only to better expose the edge 24 for assured and more effective biting engagement with the bead 12 of the cover skirt, but also to more accurately locate this edge relative to the body lip 25. At the same time, the cross-sectional shape and the thickness of the fold or lip is preserved for insuring such engagement and for maintaining the same effective seal around the entire periphery of the container in spite of dimensional variations inherently occurring in the manufacture of parts formed of sheet metal and molded resilient plastics by high speed production methods.

For this purpose, the hem flange 26 is depressed between the folded lip 25 and the free edge so that the portion 29 of the flange below the lip is inclined toward the outer wall 30 of the hem and preferably into contact with the latter at 31 about midway between its edges,

the lateral thickness and rounded cross-section of the lip resulting from the folding and reverse bending of the tube end being preserved. At the same time, the lower half portion 32 of the flange is inclined reversely and away from the outer hem wall 30 at an angle of about 30 degrees with the edge 24 spaced away from the hem wall 30 a distance a which herein is slightly greater than the thickness b of the fold or lip 25. Thus, a shallow V- shaped peripheral groove is formed between the lower half 32 of the flange and the adjacent wall 30.

Due to such inclination and as shown in FIG. 2, the edge 24 digs into the top of the skirt bead substantially at the junction of the upper inclined surface 14 and the adjacent wedge wall of the skirt 11 and is disposed substantially normal to the upper surface. With the free edge portion 32 of the flange thus inclined away from the wall 30 and toward the bead, the raw metal edge 24 is better exposed for effective biting engagement with the softer plastic upper surface 14 of the bead in the final pressed on position of the plastic cover.

Even though high speed production methods inherently cause dimensional variations in the location of the flange edge 24 relative to the lip and of the bead 12 relative to the wedge surfaces 15 and 18, these variations do not prevent the flange edge 24 from biting into the bead surface 14 of the above described skirt. Secure holding and uniform sealing of the cover onto the body 22 thus are assured around the entire periphery of the container. Such secure holding of the cover on the body is further assured by virtue of the more accurate location of the flange edge 24 relative to the lip 25. Thus, the free edge portion 32 of the flange is relatively narrow and is backed rigidly at the contact point 31 by the outer wall of the hem so that the edge 24 is less susceptible to movement with the head 12 under any force tending to remove the cover from the body.

I claim as my invention:

1. For securing a molded plastic cover against the end lip of a container body, said body comprising a tube of thin sheet metal having a short length at one end folded laterally and then bent reversely to form a flange lying adjacent the side wall of the tube and cooperating therewith to form a relatively flat hem with the fold defining a lip of rounded cross-section, said flange being depressed laterally intermediate said lip and the free edge of the flange and toward said wall whereby the portion of the flange adjacent said lip converges to said wall and the free edge portion diverges from the wall to space the free edge of the flange away from the wall a distance about equal to the radial thickness of said lip.

2. A container body as defined in claim 1 in which said flange is depressed into abutment with said side wall and rigidly backed thereby.

3. A container body as defined in claim 1 in which said free edge of the flange is spaced radially away from said side walla distance somewhat greater than the radial thickness of said lip.

4. A container having, in combination, a cover of molded plastic with two laterally spaced peripheral skirts depending therefrom and defining a downwardly opening groove, a first one of said skirts having a peripheral bead radially projecting partially across the open end of the groove with an inclined upper surface diverging away from the first skirt, a tube of thin sheet metal having a short end portion folded laterally and then reversely along the side of the tube to form a flange cooperating with said side to define a hem with the fold thereof seated in said groove, the flange being bent intermediate its ends with the free edge portion of said flange being bent away from said tube side and disposed approximately normal to said head surface with its free edge biting into the plastic of the bead to hold the two interlocked and thereby secure the cover onto the body.

References Cited UNITED STATES PATENTS 2,060,145 11/1936 Vogel 220-24 X 3,122,287 2/1 964 Makowski 222570 3,187,964 6/1965 Foster 220- X THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner. 

1. FOR SECURING A MOLDED PLASTIC COVER AGAINST THE END LIP OF A CONTAINER BODY, SAID BODY COMPRISING A TUBE OF THIN SHEET METAL HAVING A SHORT LENGTH AT ONE END FOLDED LATERALLY AND THEN BENT REVERSELY TO FORM A FLANGE LYING ADJACENT THE SIDE WALL OF THE TUBE AND COOPERATING THEREWITH TO FORM A RELATIVELY FLAT HEM WITH THE FOLD DEFINING A LIP OF ROUNDED CROSS-SECTION, SAID FLANGE BEING DEPRESSED LATERALLY INTERMEDIATE SAID LIP AND THE FREE EDGE OF THE FLANGE AND TOWARD SAID WALL WHEREBY THE PORTION OF THE FLANGE ADJACENT SAID LIP CONVERGES TO SAID WALL AND THE FREE EDGE PORTION DIVERGES FROM THE WALL TO SPACE THE FREE EDGE OF THE FLANGE AWAY FROM THE WALL A DISTANCE ABOUT EQUAL TO THE RADIAL THICKNESS OF SAID LIP. 